The invention relates to a method, particularly an automatic method, for measuring light, in which at a darkened measuring station a series of consecutively supplied samples are each supplied with a reagent, the reaction process is measured photometrically and the measuring result is further processed according to a computer program.
The invention also relates to an apparatus for carrying out this method and comprising a measuring station located in a darkened measuring chamber, a transfer section passing through the measuring chamber for supplying and removing successive discrete samples, a reagent supply system leading into the measuring chamber to supply the sample located in the measuring station, a light detector and a computing and evaluating device.
Methods and apparatus of this type are known in connection with the devices called LUMACOUNTER, Type 2080, and Celltester, Type 1030, which are sold by the firm LUMAC SYSTEMS AG, Reichensteinerstrasse 14, CH-4000 Basle 2 Switzerland.
In such a prior art device, a certain reagent is fed to the sample after the sample has been transferred to the darkened measuring station. It is also possible to inject the same reagent several times at the darkened measuring station. This device deviates from the usual practice of adding the reagent to the sample while the latter is still outside the darkened measuring station and then moving the sample to the darkened measuring station. If, however, with prior art devices of this type, several measurements must be made in succession with the successive addition of different reagents, it is necessary, after the first reagent has been added at the darkened measuring station, to remove the sample to the open air to add the next reagent whereupon the sample, together with the added reagent, is returned to the darkened measuring station; the reason is that the prior art devices of this type are not equipped for the addition of different reagents to a sample which remains at the darkened measuring station.
The prior art device of this type can be operated either fully automatically or semi-automatically, or also manually by a technician; this also applies within the scope of the invention in which the automatic, and especially the fully automatic mode of operation is preferred.
If, during successive measurements with successively added reagents, the sample is transferred from the darkened measuring station to the open air for the purpose of adding the next reagent, this may result in measuring errors due to the phosphorescence or fluorescence being superposed by the incidence of extraneous light. Within the scope of the invention, such measuring errors are considered to be more critical than superposition of fluorescence or phosphorescence which occurred when the original sample was exposed to light. This is because the resultant luminous background of the measurement averages out sooner in successive measurements of the same sample with the successive addition of different reagents, than a superposed fluorescence or phosphorescence which appears for the first time only after the first measurement.